Original publication date: January 9, 2023
Last Updated: February 9, 2024
Author: Max Skyler
Topic: Flight Physiology
Number of Comments: 0
Thyroid problems have been a perennial question mark with respect to a pilot’s fitness to fly, since the early days of FAA medical standards enforcement. Hypothyroidism and hyperthyroidism specifically have been targeted and singled out as medical conditions that require some degree of heightened scrutiny when pilots seek to obtain their medical certification. While the FAA’s crackdown on what it deems as disqualifying medical conditions could be perceived as overzealously draconic, the fact remains that its altruistic measures at ensuring public safety have proven to be quite effective, given its stellar safety record as an arm of the transportation industry on the whole.
Being diagnosed with a thyroid disorder does not automatically sound the death knell for one’s aviation career. As long as a pilot can demonstrate that their thyroid condition is being kept under control, within FAA-mandated medical parameters, they can potentially be medically cleared to fly.
The FAA provides guidance to Aviation Medical Examiners (AMEs) on how to evaluate and monitor a pilot’s thyroid disease to ensure that they are medically fit to act as pilot-in-command of an aircraft. Let’s examine how the FAA classifies thyroid problems, what a typical mitigation plan might look like, and what it takes to obtain as well as maintain medical clearance to fly.
Are Thyroid problems medically disqualifying conditions?
The FAA maintains a list of medically disqualifying conditions, which prevent a pilot from being able to be granted the requisite medical certificate necessary in order to pilot an aircraft. Having said that, these disqualifying conditions are not absolute disbarments from being able to fly. The good news is that the FAA does offer a path for pilots to reign in their medical condition and demonstrate that it is being kept under control, contingent upon which pilots may be eligible to be granted what is known as a special issuance medical certificate.
Hypothyroidism and hypothyroidism, respectively, are not on the FAA’s list of medically disqualifying conditions. However, an AME may choose to defer the decision to grant you a medical certificate if they deem that your thyroid condition is not being well-maintained, and your TSH (thyroid-stimulating hormone) level is not within an acceptable range.
On that basis, thyroid control does require greater scrutiny, not merely as a one-time check-in with an AME, but may require frequent follow-up check-ins, to ensure that you remain in compliance with the guidelines set forth by the FAA for thyroid control. Therefore, it behooves pilots to be proactive about their thyroid management and not allow oneself to become complacent with respect to it.
Whereas thyroid conditions do not automatically require a Special Issuance medical certificate, by the virtue of the fact that they are not technically classified as medically disqualifying by the FAA, hypothyroidism and hyperthyroidism both do appear on a decision matrix of general endocrine disorders. It is from here that an AME can seek guidance on how to handle each of the respective thyroid conditions.
Conditions an AME Can Issue
In order to expedite the processing of certain common disorders and diseases that can be mitigated with relative ease, the FAA maintains a list of what is known as the list of Conditions AMEs Can Issue (CACI).
The CACI confers upon AMEs the authority to issue standard medical certificates, and circumvent the need for applying for a special issuance. This can be achieved as long as the pilot is able to satisfy the criteria by which the FAA evaluates each of these conditions, respectively.
Whereas a special issuance requires the FAA to conduct a thorough, case-by-case review of your medical history and your current bout with a disqualifying condition and the regimen that you are following to mitigate it, a CACI requires less administrative oversight of your condition by the FAA. Your local AME will not need to defer the decision to issue a medical certificate to the FAA, and can instead issue it themself.
This should not, in any way, be misconstrued to imply that AMEs are somehow more “lenient” and that medical certifications are “easier” to obtain if they are considered among the items on the CACI list. Rather, it simply means that the administrative overhead required in order to issue the medical clearance to fly is greatly reduced.
Failure to satisfy the criteria, as enumerated by the FAA, could still require the AME to defer the medical certificate issuance and send supporting documentation to the FAA for further review, particularly in exceptional circumstances. In this circumstance, a special issuance certificate may still be warranted.
Insofar as the pair of thyroid disease is concerned, you will find that hypothyroidism makes this list, but hyperthyroidism does not. As of this writing, the FAA has deemed the former to be easier to regulate and issue than the latter.
Hypothyroidism Guidelines To Qualify For Medical Issuance
The FAA has published a CACI Condition Worksheet specifically geared toward addressing the issue of a pilot’s hypothyroidism. Hypothyroidism has been classified as one among the myriad of health conditions that have been earmarked for medical clearance directly by an AME, without having to defer to the FAA.
In accordance with this worksheet, the pilot must provide a current detailed clinical progress note from their treating physician, from within the prior 90 days. This note must include the following:
- A summary of the pilot’s history with hypothyroidism
- Current medications being taken, and their respective dosages
- Side effects of aforementioned medications (if any)
- Clinical exam findings
- Testing results (if any)
- Diagnosis
- Prognosis (assessment and treatment plan)
- Follow-ups
If the pilot is able to successfully meet all of the criteria enumerated on the CACI Condition Worksheet, of which the detailed clinical progress note is a requirement, then the AME may issue them a medical certificate.
If the pilot fails to meet all of these criteria, then all is not lost. The AME does not necessarily deny the pilot’s medical clearance. Rather, he has the option to defer the decision to the FAA, in which the recourse would be for the pilot to apply for a Special Issuance certificate instead.
Hyperthyroidism Guidelines To Qualify For CACI Issuance
Unlike hypo-thyroidism, for which the FAA offers a pathway to medical certification through the CACI process, hyper-thyroidism on the other hand, offers no such recourse. Pilots who are diagnosed with hyperthyroidism must go through the process of obtaining a Special Issuance medical certificate for hyperthyroidism.
If it is the pilot’s first time obtaining a special issuance certificate for hyperthyroidism, then the AME must submit all documentation either to the Aerospace Medical Certification Division (AMCD) located at the Civil Aerospace Medical Institute in Oklahoma City, Oklahoma, or to their local Regional Flight Surgeon (RFS).
If the pilot had already obtained a special issuance medical certificate for hyperthyroidism previously, and is seeking to renew it due to an impending expiration, then the FAA has authorized AMEs to be able to reissue the certificate. This is of course contingent upon a satisfactory review of all medical records pertaining to the pilot’s condition.
What are the different classes of medical certification?
The FAA issues different classes, or tiers, of medical certification, depending on what you intend to do with your pilot’s license. The Special Issuance designation is essentially a qualifier for each of these classes.
Here is a brief primer on the different classes of medical certification:
| Medical Certification Class | Required For… |
| 1st Class | Airline Transport Pilot |
| 2nd Class | Commercial Pilot |
| 3rd Class | Private Pilot |
How Does The Special Issuance Process Work?
Understanding how the Special Issuance process works requires you to understand how it differs from the issuance of a standard medical certificate.
According to the Federal Aviation Regulations (FAR) – Section 67.401, authorization for Special Issuance of a Medical Certificate, may be granted to any pilot who does not meet the criteria for receiving a standard 1st Class, 2nd Class, or 3rd Class medical certificate.
Fundamentally, the key differentiator between a standard medical certificate versus a Special Issuance medical certificate is the extra level of scrutiny that is involved in evaluating a pilot’s physical fitness to fly, due to the red flag raised by the pilot’s medical condition. It can end up being a lengthier process to obtain a Special Issuance medical certificate, to the additional testing, paperwork, and monitoring required of one’s condition. It also could equate to more frequent recertifications to ensure that the pilot’s condition remains stable and under control.
In some circumstances, the prerequisites for a Special Issuance may be satisfied through a Statement of Demonstrated Ability (SODA) in lieu of undergoing the standard authorization process.
At its core, the Special Issuance certificate is essentially a qualifier for each of these three. Therefore, the way that it works is that you would receive a Special Issuance for a 1st class, 2nd class, or 3rd class medical certificate.
BasicMed As A Viable Alternative For General Aviation Pilots
While obtaining a Special Issuance certificate may be mandatory, and may be the only path forward for pilots who aspire to fly commercially, the FAA does offer an alternative medical certification track, exclusively for general aviation pilots, known as BasicMed.
BasicMed allows general aviation pilots the ability to obtain medical clearance to fly through a far less rigorous process that involves less medical scrutiny and less bureaucratic oversight.
In fact, BasicMed empowers private pilots to achieve medical clearance to fly, through more of a self-attestation process.
Whereas obtaining a 1st, 2nd, or 3rd class medical requires you to undergo an FAA-mandated medical exam by an AME, BasicMed allows you to visit any general physician and undergo a general physical exam.
All that is needed is for a general physician to conduct a routine medical exam. Both the pilot and the physician should jointly fill out a copy of the FAA BasicMed Comprehensive Medical Examination Checklist and keep it with you. There is no need to file this checklist with the FAA, but if it is ever requested, you must be prepared to provide a copy of it. This exam must be administered and a new copy of the checklist should be completed once in every 48 calendar months.
Additionally, the pilot must take an online medical self-assignment course, every 24 calendar months, offered either through MayoClinic or through Aircraft Owners and Pilot’s Association (AOPA).
BasicMed comes with a number of restrictions and limitations on what type of aircraft you can fly and even where you can fly:
| BasicMed Restrictions and Limitations |
| You cannot carry more than 6 passengers, including yourself. |
| You cannot fly higher than 18,000 feet above sea level. |
| You cannot fly faster than an airspeed of 250 knots. |
| The weight of the aircraft (at takeoff) cannot exceed 6,000 pounds. |
| You cannot fly for compensation or for hire. |
| You may only fly within the territorial United States or in countries that accept BasicMed. As of this writing, Mexico and the Bahamas are the only two countries that recognize BasicMed. Canada does not currently recognize BasicMed at the time of this writing. |
| You must take and pass an online medical self-assessment course every 24 months. |
| You must undergo a comprehensive general physical exam, which can be administered by any general physician every 48 calendar months. |
These restrictions are generally in-line with the experience level and the capacity of most general aviation pilots. However, if you wish to fly bigger, faster airplanes, and carry more passengers, as a private pilot, then you would have no recourse but to apply for a 3rd class medical certificate. In this case, if you suffer from hypothyroidism that is under control, then you may be able to obtain medical clearance through a CACI. Otherwise, if you suffer from hyperthyroidism, or your hypothyroidism isn’t being properly maintained, then a Special Issuance may be required.
BasicMed And Thyroid Issues
As long as the general physician is satisfied, as a result of the general physical exam, that you do not harbor any overt or underlying medical conditions that could potentially interfere with, pose a risk to, or jeopardize your ability to safely operate an aircraft, then they have the liberty to sign you off for flying. Even if you do suffer from thyroid issues, and you adequately disclose your treatment regimen, which includes any medication you are taking to keep it under control, then the physician should have no issue with signing you off for it.